Glass-surface-working tool.



R. STRAUBEL.

GLASS SURFACE WORKING TOOL.

APPLIOATION FILED JULY 22, 1907.

1fp975 5 Patented May 19, 1914.

UNITED STATES PATENT omen.

RUnoLr s'raaunnn, or JENA, GERMANY, nssxenon TO THE FIRM or cam. znrss, or

. JENA, GERMANY.

emss-suarnon-woaxme TOOL.

Specification of Letters Patent.

Patented May 19, 1914.

Application filed July 22, 1907. Serial No. 385,337.

To all whom, it may concern:

Be it known that I, RUDOLF STBAUBEL, doctor of philosophy, a citizen of the German Empire, and residing at Carl-Zeiss strasse, Jena, in the Grand Duchy of Saxe- Weimar, Germany, have invented a new and useful Glass-'Surface-Working Tool, of

' which the following is a specification.

Up to the present time for the rough grinding of glass surfaces emery and similar grits in loose form have been placed between the surface to be ground and a suitably formed surface subjected to pressure and then a suitable relative motion provided for the two surfaces. Occasionally instead of loose grit rotating emery disks have been employed. The drawback of both means is that the abrasion of the glass is not sufficiently plentiful.

The present invention proposes a substitute for the emery disk, that is to say,

another rotating tool, in the employment of which the abrasive efiect obtained by the older means is vastly increased. This new tool is given the form of a roller or other body of revolution and consists of a tough, that is to say, a ductile and tenacious metal, for instance, copper.

embedded, not necessarily at regular intervals' apart, but at any rate so distributed,

that the average distance between grain and grain amounts to a high multiple of the average diameter of the grains. This diamcter ought to be chosen for most purposes as large as 1/10 mm. For abrading large quantities of glass grains of larger dimensions, say up to- 1/2 mm. are still more advantageous, while on the other hand the abrasive eifect or the durability of the tool sinks rapidly, when the dimensions of the grains fall below 1/15 mm. Glass grinding with such a rotating diamond tool necessitates a copious supply of a perfectly wetting fluid, for instance, petroleum, between the glass surface being ground and the grinding surface. The grains of grit can be pressed into the roller. It is, however, a better method to make indentations in the superficial layer of the metal beforehand, for instance, by'chiselin and then firmly jamming the grains un' erneath the burs of these indentations.

Rotating tinrplate disks moistened by In the superficial layer grains of diamond grit are pressed into their working surfaces.

Figure l is a side View of a glass surface working tool according to the invention. Fig. 2 is a front view of the"same tool. Fig. 3 is a partial cross se ction through the same tool on an enlarged scale; Fig.

4 is a partial plan view of'the same tool,

likewise on an enlarged scale. Fig. 5 is a partial plan view of a similar tool, again on an enlarged scale.

The working surface (12 of the tool a, while being in each case a surface of revolution, in the example s own is cylindrical, its axis being the axis .of rotation of the tool, as indicated by the arrow in Fig. 2. The surface a is set with diamond grit, the grains 2) of which are jammed underneath the burs of indentations c chiseled in the superficial layer of the tool. There may be, for example, long straight indentations, as in Fig. 4, each containing a lot of grains, and small indentations, as in Fig. 5, each containing one grain only or a few grains at most.

I claim: Glass surface workin tool comprising a body of tough metal wit a surface of revolution, grains of diamond grit between 1/2 mm. and 1/15 mm. diameter being jammed underneath the burs of indentations in the layer-of metal under said surface, these indentations deviating from the radial direction all toward the same side in the plane of revolution and the grains being so distributed over the surface of revolution that the average distance between adjacent grains is a high multiple of the average diameter of the grains.

' RUDOLF STRAUBEL. Witnesses:

PAUL Knt'ronn, Fnrrs SANDER. 

